Stabilizing motor fuels



Patented Apr. 30, 1935 STABILIZING MOTOR FUELS William S. Calcott,Pennsgrove, N. J.,

Lee, Wilmingtom'DeL,

Pont de N emours &

and Ira E. assignors to E. L dn Company, Wilmington,

Del., a corporation of Delaware No Drawing. Application May 20, 1933,Serial No. 672,046

8 Claims.

This invention relates to improvements in means for stabilizing motorfuels comprising cracked hydrocarbon spirits and; more particularly, toimproved materials for use with cracked gasolines which may be employedas motor fuels.

It is well known that cracked gasoline tends to deteriorate on storagewith the formation. of gummy and resinous products. Motor benzol alsocontains cracked hydrocarbon spirits which tend to form gummy andresinous products. It is also well known that some petroleum oilsnaturally contain crackedj hydrocarbon spirits formed by the heat andpressure to which the petroleum. oil was subjected under the earth.

When such a petroleum oil is subjected to distillation and the lighteror gasoline fractions collected, such gasoline fractions contain crackedhydrocarbon spirits which tend to form gummy and resinous products.

An object of the present invention is to re tard the formation of gummysubstances in motor fuels comprising cracked hydrocarbon spiritsnormally tending to form gummy substances on storage. A further objectis to provide new and improved means for stabilizing motor fuels. Astill further object is to provide new compositions of matter comprisingmotor fuels normally tending to form gum and substances which retard theformation of such gum. Other objects are to advance the art. Still otherobjects will appear hereinafter. v

These objects may be accomplished according to our invention whichcomprises treating a motor fuel, containing cracked hydrocarbon spiritsnormally tending to form gummy substances, with an alkoxy substituteddihydroxy benzene in an amount sufficient to retard the formation of thegummy substances. Of the alkoxy dihydroxy benzenes, we have found themethoxy dihydroxy benzenes to be the most satisfactory for our purpose.The methoxy dihydroxy benzenes illustrated by phloroglucinol-mono-methylether have been disclosed in our Patent 1,884,559 granted October 25,1932. Another methoxy dihydroxy benzene which we have found to beparticularly satisfactory is pyrogallol l-methylether.

' The method employed for testing the eflectiveness of the compoundsused was essentially that described by Voorhees and Essinger in J. S. A.E.

24, 584 (1929). In this test, 100 cc. of the cracked gasolineis heatedin a glass flask under an oxygen atmosphere at 100 C. The flask isconnected to a mercury manometer and themessure observed at regularintervals. The time in minutes from the start of the test until thegasoline begins to absorb oxygen; as shown by-the fall in pressure, isknown as the inductionperiod of the gasoline. The eifectiveness of a guminhibitor is measured by the increase in indu'ctionperiod caused by theaddition of a givenquantity of the inhibitor. That the'induction periodis directly related to gum formation can be shown by interrupting twotests of the same gasoline, one just before and the other just after theinduction period is reached, and determining the gum content of eachsample of gasoline. The amount of gum present after the induction periodis reached is several times greater than the amount present in the othersample. I 'In order to more clearly illustrate our-invention and thepreferred mode of carrying thesame into efiect, the following example isgiven:

Example To a gum-free unsaturated gasoline normal- 1y having aninduction period of minutes was 3-Hydroxy hydroquinoneel-methyl ether noon 2-Hydroxy hydroquinone-l-methyl ether OCH! 1 n Methory-hydroquinoneOther mono-ethers of the trihydroxy benzenes, such as theethoxy-dihydroxy benzenes and higher homologues may also-be mentioned.However, they will be found to be less eflieient on a weight basisbecause of their higher molecular weight.

The amount of the'gum inhibitor which it is necessary to employ willvary with the nature and concentration of the unsaturated constituentsof the cracked hydrocarbon spirits and the degree of stabilization it isdesired to obtain. In general; however, the concentration of the guminhibitor in cracked gasoline will be substantially less than 0.1% byweight.

While we have described the preferred embodiments of our invention, itwill be readily apparenttothoseskilledintheartthatmany modifications 4 dvariations may be made therein without departing from the spiritthereof.

. Accordingly, the scope of our invention is to be.

limited solely by the appended claims construed as broadly as ispermissible in view of the prior We claim:

\ spirits 1. Motor fuel comprising cracked hydrocarbon normally tendingto form gummy subspirits normally tending to form gummy substances onstorage having incorporated therein a pyrogallol mono-alkyl ether in anamount sumcient to retard the formation of the gummy substances.

4. Motor fuel co prising cracked hydrocarbon spirits normally tending toform gummy substances on storage having incorporated therein apyrogallol mono-methyl ether in an amount sufficient to retard theformation of the gummy substances.

5. Cracked gasoline normally tending to form gummy substances on storagehaving incorporated therein an alkoxy substituted dihydroxy bention ofthe gummy substances.

6. Cracked gasoline normally tending to form gummy substances on storagehaving incorporated therein a methoxy substituted dihydroxy benzene inan amount sufllcient to retard the formation of the gummy substances.

7. Cracked gasoline normally tending to form gummy substances on storagehaving incorporatzene in an amount suiilcient to retard the formaedtherein a pyrogallol mono-alkyl ether in an amount sufllcient to retardthe formation of the substances. 8. Cracked gasoline normally tending edtherein a pyrogallol mono-methyl ether in an amount suflicient to retardthe formation of the gummy substances.

c WILLIAM S. CALCO'I'IL IRA E. LEE.

to form gummy substances on storage having incorporat-

